Metal-punching press



Aug. 26 1924.

M. NEAL METAL PUNCHING PRESS Filed Dec. 29 1922 2 Sheets-Shoat l INVENTOR mmfim M w TTORNEYJ' M. S. NEAL METAL PUNCHING PRESS Filed Dec. 29 1922 -2 Sheaxa-Shect 2 INVENTOR Wm \FKM Patented Aug. 26, 1924.

' UNITED STATES MORRIS S. NEAL, OF COLLINSVILLE, CONNECTICUT.

METAL-PUNCHING PRESS.

Application filed December 29, 1922. Serial No. 609,580.

To all whom it may concern Be it known that I, Momus STANLEY NEAL, a citizen of the United States, a resident of Collinsville, in the county of Hartford and State of Connecticut, have invented a certain new and useful Metal-Punching Press, of which the following is a specification.

The invention relates to a press adapted to punch holes in hot metal for example to form the eyes in hatchets, picks, mattocks, axes, and similar tools.

The primary object of the invention is to provide a press of the above character in which the punch is so related to the dies with which it cooperates as to minimize breaking of the punch during the punching operation.

Further objects and advantages of the invention will be in part obvious and in part specifically pointed out in the description hereinafter contained which, taken in connection with the accompanying drawings, discloses a preferred embodiment thereof. Such embodiment, however, is to be considered merely as illustrative of its principle.

. In the drawings,

Fig. 1 is a front elevation of a portion of a punching press constructed in accordance with the invention.

.Fig. 2 is a rear elevation of the structure shown in Fig. 1.

Fig. 3 is a bottom view partly in section of a ortion of the head of the punching press.

he invention relates particularly to the class of metal punching presses in which the operation of punching out the hole in the metal blank is accompanied by a shaping operation on the exterior of such blank, this latter operation being accomplished by lat eral pressure from the dies within which the blank is carried and the lateral pressure being applied in conjunction with the forward movement of the punch.

The dies or the jaws which carry them, for example, may be pivoted at their lower ends and so related to the reciprocating head ofthe machine that when the latter advances toward the jaws, the jaws are forced together by cooperating cam surfaces on the above parts.

In machines of the above type the penetration of the relatively cold punch into the hot metal blank, as well as the engagement of the relatively cold .dies with the outer surfaces of the blank, causes the latter to cool quite rapidly during the punching operation and at the same time the punch is expanded due to the heat imparted to it by the blank. The contraction of the blank and expansion of the punch as above described, as well as the lateral pressure of the dies against the blank, cause the punch to stick within the blank with the result that the punches are often broken.

In accordance with the present invention I so construct the machine that at the time when the punching operationv is completed, or substantially completed, and when the jaws which carry the dies have been forced together by the head sufficiently to perform their intended function, the dies or the jaws carrying the same are relieved from this lat eral pressure previous to the time when the head has moved upwardly far enough to release the jaws; thus the withdrawal of the punch from the hot blank takes place without any lateral pressure on the blank tending to pinch the same against the punch and cause the latter to bind. Preferably the pressure of the dies is released slightly before the punch has penetrated to its full extent. Under such conditions the punch may be withdrawnmuch more easily and without imposing undue strains thereon.

The present embodiment of the invention is disclosed as applied to the punching press having a base 1 carrying a bed plate 2 upon which two die carriers 3 are mounted in such manner that they may move laterally toward and from each other; in the present instance such die carriers are pivoted upon studs 4 carried by the bed plate 2. The machine also includes a reciprocating head de noted generally by numeral 5 which slides in suitable guides 6 carried by uprights 7 extending from the bed plate 2, the reciprocating motion being imparted to head 5 by means of a crank 8 cooperating with a pitman 9 extending from head 5. As the general structure of presses of this type is well known, the same will not be described in greater detail herein, the illustrated machine being merely an example of the class of machinery to which the invention. is ap-. plicable.

As shown, the head 5 is provided with recesses 10 (Fig. 3) adapted to receive loosely the upper ends of die carriers 3 during the downward movement of the head. A pair of rollers 11 rotatably carried by spindles 12 are provided in the head and positioned to engage the inclined cam surfaces 13 on die carriers 3 during the downward travel of the head. Thus, as punch 14 passes through the hot metal blank, the rollers 11 will force together die carriers 3 until such rollers pass beneath the above mentioned cam surfaces onto the backs of the die carriers which at that time are positioned vertically. The dies and the metal pleted. In the illustrative embodiment of the invention the spindles 12 which carry rollers 11 are provided with hearing portions 15 eccentric to the axes of the intermediate parts of: spindles 12 which support I rollers 11; thus, if the spindles 12 are moved angularly in opposite directions, the rollers 11 will be caused to move toward or away from each other as the case may be. In the present instance the rear ends of spindles 12 are each provided with an arm 16 which normally is held in] such position that the rollers 11 are relatively closeto each other, as by a dog 17 (Fig. 2) slidable in one or more bearings 18 carried by. the head and pressed forward by a spring 19 in such manner that a notch 20 therein engages the end of the arm 16. A spring 21, however, urges the arm 16 to move to a position which will cause the corresponding roller 11 to move away from the die carrier 3 and release the lateral pressure therefrom; thus, if the dog 17 be withdrawn from the end of arm 16 at or near the bottom of the stroke of head 5, the roller 11 will cause the lateral pressure to be released from die carriers 3.

In the present instance the arm 16 is released from dog 17 by means of a rod 22 sliding in suitable bearings 23 on the rear of head 5 and normally held in elevated position by means of a spring 24 engaging a collar 25 on the rod; but at or near the lower limit of travel of head 5 a lug 26 adjustably mounted on crank 8 engages the upper end of rod 22 and forces the latterdownwardly against an ear 27 on dog 17, thus releasing the end of arm 16 and permitting the latter to move upwardly'under the action of spring 21.

The rollers 11 then remain in relatively separated position until the head 5 has moved upwardly toward the highestpoint in its stroke, at which time the rollers are reset to their proper position (relatively close to each other) for applying the desired lateral pressure to the dies during the downward stroke of the head. As shown, the

rollers are reset by means of stop members 28 extending upwardly from the base 1 of the machine and passing through slots 29 in arms 16, such stop members normally passing loosely through the arms but being provided with abutments 30 which engage the upper sides of arms 16 when the head 5 approaches the upper limit of its stroke; thus, as the upper movement of thehead continues, the abutments 30 cause the arms 16 to move angularly in a downward direction until the ends of the arms are forced over the inclined surfaces 31 on dog 17, the result being that the end of arm 16 is again seated in notch 20.

The head 5 then moves downwardly and rollers 11 apply lateral pressure to the die carriers 3 during the punching operation until the head is at or near the lower limit of its stroke when the lateral pressure is again released by rod 22 in the manner above described.

lVhile the specific embodiment of the in vention has been described, it Will be obvious that many changes may be made there in without departing from its spirit as defined in the following claims:

1. A metal punching press, comprising dies, means for supporting said dies to permit relative lateral movement therebetween,

a head reciprocable relative to said dies and 1 provided with means to apply lateral pressure to sald dies during forward movementof said head, and means for releasing said lateral pressure near the limit 'of such forward movement. c

2. A metal punching press, comprising dies, means for supporting said dies to 'permit relative lateral movement therebetween, a head reciprocable relative to said dies and provided with means to 'applylateral pressure to said dies during forward movement of said head, and meansfor permitting said dies to separate laterally near the limit of r such forward movement of the head.

3. A metal punching l press, comprising dies, means for supporting said dies to per mit relative lateral movement therebetween, a head reciprocable relative to said dies, 00- operating cam parts being associated respectively with said head and dies whereby lateral pressure is applied to the dies during forward movement of said head, and means operative near the limit of such forward movement for relatively separating said cam parts to release the lateral pressure previously applied thereby.

4:. The combination set forth in claim 3, together with means operative near the upper limit of movement of the head for returning said cam parts into position to apply lateral pressure during forward movement of said head.

5. A metal punching press, comprising dies, means for supporting said dies to permit relative lateral movement therebetween, a head reciprocable relative to said dies, said head being provided with rollers adapted to engage cam parts associated with the dies to apply lateral pressure to said dies during forward movement of said head, and means operative near the limit of the forward movement of the head to separate said rollers to release the lateral pressure.

6. The combination set forth in claim 5, together with means operative near the upper limit of movement of the head for returning said rollers into position to apply lateral pressure to the dies during forward movement of said head.

7. A metal punching press, comprising dies, means for supporting said dies to permit relative lateral movement therebetween, a head reciprocable relative to said dies and provided with means to apply lateral pressure to said dies during forward movement of said head, a crank shaft for reciprocating the head, and means controlled by the position of said crank shaft for releasing said lateral pressure near the limit of the forward movement of the head.

8. A metal punching press, comprising dies, means for supporting said dies to permit relative lateral movement therebetween, a head reciprocable relative to said dies and carrying rollers adapted to cooperate with cam parts associated with the dies to apply lateral pressure to said dies during forward movement of said head, an eccentric mounting for said rollers, an arm resiliently urged toward a position to separate said rollers, a releasable dog adapted to engage said arm to hold the rollers in pressure applying position, a crank shaft for moving said head, and an arm actuated by said crank shaft for moving said dog to release said arm.

9. The combination set forth in claim 8, together with a stop member adapted to engage the arm near the upper limit of movement of the head and reengage said arm with said dog.

In testimony that I claim the foregoing, I have hereunto set my hand this 8 day of September, 1922.

MORRIS S. NEAL. 

